CryptographicEngine.Sign(CryptographicKey, IBuffer) Method

Definition

Namespace:

Windows.Security.Cryptography.Core

Signs digital content. For more information, see MACs, hashes, and signatures.

public:
 static IBuffer ^ Sign(CryptographicKey ^ key, IBuffer ^ data);

 static IBuffer Sign(CryptographicKey const& key, IBuffer const& data);

public static IBuffer Sign(CryptographicKey key, IBuffer data);

function sign(key, data)

Public Shared Function Sign (key As CryptographicKey, data As IBuffer) As IBuffer

Parameters

key

CryptographicKey

Key used for signing.

data

IBuffer

Data to be signed.

Returns

IBuffer

The data's signature.

Examples

public IBuffer SampleCreateHMAC(
    String strMsg,
    String strAlgName,
    out IBuffer buffMsg,
    out CryptographicKey hmacKey)
{
    // Create a MacAlgorithmProvider object for the specified algorithm.
    MacAlgorithmProvider objMacProv = MacAlgorithmProvider.OpenAlgorithm(strAlgName);

    // Create a buffer that contains the message to be signed.
    BinaryStringEncoding encoding = BinaryStringEncoding.Utf8;
    buffMsg = CryptographicBuffer.ConvertStringToBinary(strMsg, encoding);

    // Create a key to be signed with the message.
    IBuffer buffKeyMaterial = CryptographicBuffer.GenerateRandom(objMacProv.MacLength);
    hmacKey = objMacProv.CreateKey(buffKeyMaterial);

    // Sign the key and message together.
    IBuffer buffHMAC = CryptographicEngine.Sign(hmacKey, buffMsg);

    // Verify that the HMAC length is correct for the selected algorithm
    if (buffHMAC.Length != objMacProv.MacLength)
    {
        throw new Exception("Error computing digest");
    }

    // Return the HMAC.
    return buffHMAC;
}

Remarks

If the key is a persisted key and the operation requires UI or takes a long time, use the SignAsync method instead.

For more information about signing digital data, see MACs, hashes, and signatures.